1781, A British patent was issued for the first compound steam engine to Jonathan Carter Hornblower (No. 1298). His invention used two cylinders of unequal size attached to the same beam. Steam acts first in a small high-pressure cylinder, and then enters a larger cylinder at a lower pressure, but still sufficient to expand further. The idea was not further pursued as the increase in efficiency claimed was not achieved. But his compound steam engine principle was later revived in 1804 by Arthur Woolf using higher input steam pressure with better results.

1897 -, Guglielmo Marconi received U.S. patent for a wireless telegraph (No. 586,193).
1937 - Patent was issued to Leroy C. Lind for the Servi-Soft water softener (U.S. No. 2,087,157).